The present invention relates to a novel and useful apparatus or system for repairing a tear in an anatomical structure such as soft and connective tissue. For example, a meniscus tear may be the subject of use of the apparatus of the present application in the human knee.
A meniscus tear is a common injury caused by forceful twisting of the knee, usually during participation in vigorous or sports activities. Each knee of a human anatomy includes a pair of menisci. Each meniscus is a rubbery C-shaped disc that cushions the knee and provides steadiness during ambulatory motion.
Surgery is often performed to repair tears in a meniscus by the use of implants such as darts, anchors, sutures and other devices. Such surgery is desirable to maintain meniscal cushioning and stability of the knee joint and prevent premature arthritis.
Repair of a tear in a meniscus can be performed sing various techniques, such as open, arthroscopic with external incisions, or solely arthroscopic procedures. The open technique accesses a tear in a meniscus through large outside incisions. An arthroscopic with external incisions technique uses an arthroscope to visualize a tear while outside incisions are used to complete the repair. Both techniques requiring outside incisions increase the risk of injury to vulnerable tissues.
In contrast, an all-inside technique places arthroscope and instruments solely within the joint and accomplishes repair without larger outside incisions. Such inside technique is preferred because it avoids risks associated with the larger outside incisions. However, instruments of the prior art limit a successful all-inside technique repair to a narrow range of tears.
Optimal meniscal repair requires correct placement of an implant perpendicular to the long axis of a tear. To achieve an optimal all-inside repair, an instrument must be able to 1) access the tear, 2) align properly with the tear, 3) minimize any deforming force at the tear by insertion of an implant in optimal alignment, and 4) insert an implant at optimal depth.
All-inside instruments of the prior art generally hold or house the repair implant within a distal portion or tip of a delivery cannula for deployment. However, a repair implant, in certain cases, may be initially held by a delivery cannula apart from the distal portion or tip, e.g. at the mid-portion, and then advanced to the tip for deployment. These prior art all-inside instruments are pushed or utilize a pushing force to deliver a repair implant at a tear site. Pushing a straight instrument aligned perpendicularly to the long axis of a tear minimizes a lateral shear force at the tear. Pushing an instrument obliquely to the optimal perpendicular angle of insertion generates a deforming lateral shear force at the tear site and produces a buckled, deformed, and weak repair. Moreover, prior art instruments can be utilized in only a limited area (posterior) of a meniscus because anatomic constraints prevent optimal alignment of instrument with a tear.
Certain all-inside instruments of the prior art have an angulated distal portion or tip to improve alignment with a tear in a meniscus. With this angulation, the axis of the angulated tip diverges from axis of the proximal portion or handle of the push operated instrument. However, when such handle is ‘pushed’ to advance instrument at a tear site, the distal tip advances along the axis of instrument handle and not along the axis of the angulated distal tip. Since the axis of the handle diverges from correct direction of insertion, a lateral shear force is generated at the tear as the implant is ‘pushed’ across tear, again creating a deformed and weak repair.
In addition, a practitioner pushing an instrument of the prior art can misperceive resistance during insertion of the instrument tip. As a result, an implant may be inserted at an improper depth. Over penetration of an implant risks damage to adjacent structures, while under penetration risks poor fixation and weakened repair.
In the past, systems have been proposed to repair tissue such as meniscus tears. For example, U.S. Pat. Nos. 5,059,206, 5,500,000, 6,551,343, and US Patent Publication 2010/0010497 show systems for inserting meniscus repair devices in which a dart-like member is passed across a meniscus tear and left in place as an implant.
U.S. Pat. Nos. 6,306,159, 7,608,092, 8,006,700, and US Patent Publication 2002/0019649 describe meniscus repair devices using anchors that are inserted by pushing across a meniscal tear and securing the anchors by way of sutures or the like.
United States Patent Publication 2010/0249835 teaches a medical device for repairing tissue in which a conduit is provided to facilitate transfer of blood from a vascular region of tissue to a damaged tear. The conduit is secured by filaments that are positioned adjacent the tear walls.
U.S. Pat. No. 7,871,440 describes a unitary surgical device in which two groups of devices are shown in the form of anchors or a matrix material. The two devices are delivered from a base that is pushed into the vicinity of the tissue, such as a meniscus.
An apparatus which is capable of repairing tears without buckling, such as meniscal tears of various types, would be a notable advance in the medical field.